It's also worth considering that vaccines can't rip, get lost, or be installed incorrectly. It also protects the user no matter where they go-- they don't have to stay in bed to be protected. 

Even if slightly more expensive, vaccines seem like they might be more convenient for the people who need protection from malaria.

I wonder though if there are other major mosquito-borne diseases that bed nets protect from besides malaria. If there are, then a combination of nets+vaccine seems best. 

Context: there has recently been a new phase 1/2b RCT in The Lancet, confirming a ~80% effectiveness rate for the R21/MM malaria vaccine (and confirming that booster shots work). 

Quoting https://www.bbc.com/news/health-62797776:

'Prof Hill said the vaccine - called R21 - could be made for "a few dollars" and "we really could be looking at a very substantial reduction in that horrendous burden of malaria".

He added: "We hope that this will be deployed and available and saving lives, certainly by the end of next year."'

If the vaccine makes it through phase III trials, this seems intuitively like a much more effective malaria intervention than bednets.

Suggestion here that the cost is $5 a dose https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0244995 which seems very likely to push it into cost-effective territory surely? (assuming distribution costs etc aren't absolutely enormous)